Mascara brush with small diameter bristle fibers

ABSTRACT

A mascara brush for a low viscosity mascara product has a typical twisted wire core containing bristles having a relatively small diameter and relatively high bristle density. The bristles have a diameter of from 0.0001 inch to about 0.004 inch, preferably 0.0005 inch to 0.003 inch, and most preferably 0.001 to 0.003 inch. The bristle density is in the range of 18-175 bristles per turn; depending on the bristle diameter.

FIELD OF THE INVENTION

[0001] The present invention relates to a brush for applying cosmeticproducts, in particular, mascara, to eyelashes.

BACKGROUND OF THE INVENTION

[0002] Twisted wire brushes for application of liquid-type cosmetics,such as for application of mascara to the eyelashes, are well known inthe art. The brushes are designed to pick up and hold a supply ofmascara from the cosmetic container, and then deliver the mascara to theeyelashes as the brush is combed through the lashes by the user.

[0003] Twisted wire brushes conventionally are manufactured by disposinga plurality of individual lengths of bristles transverse to and betweensubstantially parallel, slightly spaced-apart thin metal wire lengths,such that the wire lengths generally bisect the filament lengths attheir midpoints. Most typically, the parallel wire lengths comprise thetwo substantially equal leg lengths formed from bending a single lengthof wire into a U-shaped configuration. The wire lengths are then twistedtogether to form a helical core, causing the bristles disposed betweenthe wires to be clamped therebetween at about their midpoints. In thetwisting and clamping, the segments of the bristles on either side ofthe clamped midpoint are caused to flare radially outward from the coreand so form an elongate bristle brush portion of generally circularcross-section. The brush is generally provided with a handle which cancomprise, or be affixed to, a cap or other closure for the cosmeticcontainer.

[0004] It is known in the art that this helical wire twisting method forforming cosmetic applicator brushes typically leads to a brushconfiguration in which the bristles tend generally to follow the helicalpattern of the twisted wire core, i.e., whereby the tips of the bristlesdefine a helix. The degree of axial spacing between turns of the helixvaries depending on the number, type and thickness of bristles employed,the wire thickness employed, the number of helical twists used informing the wire core, and other like factors. See, for example, U.S.Pat. No. 4,887,622 to Gueret, and U.S. Pat. No. 4,733,425 to Hartel etal.

[0005] The bristles are usually comprised of nylon filaments. Thebristles serve the function of collecting mascara from a reservoir andholding the mascara until it is applied to the user's eyelashes.Standard mascara brush designs of the 1960s and 1970s used filamentsused smaller diameter bristles in fairly large numbers of bristles perturn (typically, 0.005 inch (5 mil) diameter filaments with a bristlecounts in the range of 50 bristles per turn).

[0006] The state of the art then evolved to a somewhat larger diameterbristle, as defined in U.S. Pat. No. 4,887,622 entitled “Brush for theApplication of Mascara to the Eyelashes.” The patent discloses a mascarabrush having a reduced number of bristles, said to be 35% to 80% lessthan in conventional mascara brushes, ostensibly of larger diameter,than the bristles employed in conventional mascara brushes at the time.This was believed to provide a better application of mascara andseparation of lashes. The patent specifies mascara brushes having abristle diameter from about 0.10 to 0.25 mm (e.g. about 0.004 to 0.010inch) (4 mil to 10 mil) and with from approximately 10 to 40 bristlesper turn of the helix.

[0007] The concept of a mascara brush having larger diameter fibers wasfurther discussed in a recent PCT application no. PCT/US01/04555. Thisapplication is directed towards mascara brushes made from filaments thatare relatively large but soft. Specifically, the application describesmascara brushes having preferably having 7-14 bristles per turn. Thebristle filaments are defined as preferably being from 0.010 inch to0.013 inch (10 mil to 13 mil). Most critically, the bristles are definedas being relatively soft being made of a thermoplastic elastomer havinga durometer of between 62 Shore D and 82 Shore D, but most preferablyabout 72 Shore D. PCT application PCT/US01/04555 essentially defines amascara brush made with a duPont Filaments filament sold under thetrademark “Supersoft.” The “Supersoft” filaments have a durometer of 72Shore D and are available as solid filaments or as triocular filamentshaving three hollow voids.

[0008] The state of the art then has been moving in the direction oflarge diameter bristle fibers, mainly to accommodate high viscositymodern mascara formulations. The viscous mascara formulations have beenfavored because they provide a thicker application of mascara with fewerstrokes. Mascara, which is typically highly viscous, tends to clump whenapplied to eyelashes. The clumps of mascara are typically combed out asa finishing step to the application process. Stiffer bristles arethought to be better suited for combing out clumps and properlyseparating lashes. However, the combing and separating functions arethought to be better accomplished with brushes a having relatively openbristle envelope or brush surface, i.e., an envelope or surface that hasnumerous or wide clearances or spaces between bristles to make thebrushes more ‘comb-like’. This function is not well served bytraditional mascara brush designs having smaller diameter bristles withhigher bristle density.

[0009] Very recently, there has been a new trend in mascaraformulations, towards a more fluid product. This product requires acompletely different mascara brush than the types of brushes which haveproposed in the past decade. The present invention proposes a new brushproviding a desirable fast application and coating of a consumer'seyelashes with mascara using a less viscous, more fluid mascara product.

SUMMARY OF THE INVENTION

[0010] An improved mascara brush has a typical twisted wire corecontaining bristles having a relatively small diameter and relativelyhigh bristle density. The bristles have a diameter of from 0.0001 inchto about 0.004 inch, preferably 0.0005 inch to 0.003 inch, and mostpreferably 0.001 to 0.003 inch. The bristle density is in the range of18-175 bristles per turn; depending on the bristle diameter.

[0011] The combined decrease in diameter and increase in bristledensity, used with a low viscosity mascara product yields a brush suitedfor rapid application of a mascara product.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a side elevation view of a mascara brush in accordancewith the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0013] Referring now to FIG. 1, a mascara applicator brush, designatedgenerally by reference numeral 10, is shown. The brush is intended foruse in a typical mascara bottle (not shown) with an opening into whichthe brush 10 is inserted.

[0014] The brush 10 is comprised of a central twisted wire core 12containing bristles 14. The core 12 is a twisted wire core typicallymade by forming a soft metal wire 16 into a “U” shape. A plurality ofbristles 14 are placed between the segments 18 of wire 16. The wiresegments 18 are then twisted about the longitudinal axis to clampbristles 14 at approximately a midpoints of the bristles 14. The bristleends extend radially from the twisted wire core 12. Core 12 has a lowerend 20 connected to a shaft, and an upper end 24 opposite the lower end20. The lower end 20 of the core 12 is connected to a handle by way ofthe shaft, however, the lower end 20 of the core 12 could alternativelybe attached to another structure such as a bottle cap.

[0015] After the bristles 14 are mounted to the wire core 12 the brush10 can be trimmed to have any desired shape, for example, cylindrical,tapered, conical, curved, etc.; or if desired, the bristle ends may beprocessed by grinding, heating, or other techniques.

[0016] The bristles have a diameter of from 0.0001 inch to about 0.004inch (0.1 mil to 4 mil), preferably 0.005 inch to 0.003 inch (0.5 mil to3 mil), and most preferably 0.001 to 0.003 inch (1 mil to 3 mil).

[0017] Bristles 14 are preferably made by cutting short segments fromspools of filaments. The filaments are preferably formed from nylon orpolyester, or another suitable material. The filaments will typically becircular solids in cross-section, but alternatively may havenon-circular cross-sectional shapes, or may have voids therein, thus,the term “diameter” as used herein is intended to mean the maximumdistance between any of the possible opposite positions on the outersurface of a bristle filament.

[0018] The bristle density is in the range of 18-175 bristles per turn;depending on the bristle diameter and the viscosity of the mascaraproduct. The bristle density and the bristle diameter are inverselyrelated, in that as bristle diameter increases, the related bristledensity will decrease.

[0019] Typical preferred combinations of a bristle diameter range and abristle density range will be as follows: Diameter (Inches) Density(Bristles/turn) .0001 to .00049 200-60 .0005 to .00099 180-40  .001 to.0019 175-30  .002 to .0029 120-22  .003 to .004  60-18

[0020] The number of bristles per turn can be determined by severalmethods. One method involves counting bristle ends in one 360 degreeturn of the brush and dividing by two to arrive at a count of bristlesper turn. Another method involves counting the total number of 360degree turns of the bristles of the brush along the length of the brush,then counting the total number of bristles, and dividing the totalbristle count by the total turn count, to determine an average ofbristles per turn. It is contemplated that in a basic brush, there willbe a substantially constant bristle density along the length of thebrush, with a small variations depending on manufacturing precision.However, it is also possible that the bristle densities are an averagebristle density, with greater variation in the bristle density betweendifferent zones (such as the ends versus the middle zones of the brush).As used herein, “bristle density” encompasses both definitions.

[0021] In combination, the smaller diameter and the higher bristledensities yields a brush that is excellent in fast and effectiveapplication of lower viscosity mascaras to the eyelashes. The mascarabrush of the invention provides uniform coating of lower viscositymascaras on eyelashes.

[0022] While the invention has been described and illustrated asembodied in preferred forms of construction, it will be understood thatvarious modifications may be made in the structure and arrangement ofthe parts without departing from the spirit and the scope of theinvention recited in the following claims.

What is claimed is:
 1. A brush for applying mascara to eyelashes,comprising: a twisted wire core holding a plurality of radiallyextending bristles to form a brush at an end of the core, said bristleshaving a diameter of between about 0.0001 inch to about 0.004 inch, saidbristles being provided at a bristle density of between about 18 toabout 175 bristles per turn.
 2. A brush in accordance with claim 1,wherein the bristles have a diameter of about 0.0005 inch to 0.003 inch.3. A brush in accordance with claim 1, wherein the bristles have adiameter of about preferably 0.001 inch to 0.003 inch.
 4. A brush inaccordance with claim 1, wherein the bristles have a diameter of about0.0001 inch to 0.00049 inch and a bristle density of 200−60 bristles perturn.
 5. A brush in accordance with claim 1, wherein the bristles have adiameter of about 0.0005 inch to 0.00099 inch and a bristle density of180−40 bristles per turn.
 6. A brush in accordance with claim 1, whereinthe bristles have a diameter of about 0.001 inch to 0.001 9 inch and abristle density of 175−30 bristles per turn.
 7. A brush in accordancewith claim 1, wherein the bristles have a diameter of about 0.002 inchto 0.0029 inch and a bristle density of 120−22 bristles per turn.
 8. Abrush in accordance with claim 1, wherein the bristles have a diameterof about 0.003 inch to 0.004 inch and a bristle density of 60−18bristles per turn.
 9. A brush for applying mascara to eyelashes,comprising: a twisted wire core holding a plurality of radiallyextending bristles to form a brush at an end of the core, said bristleshaving a diameter of between about 0.0001 inch to 0.00049 inch and abristle density of 200−60 bristles per turn.
 10. A brush for applyingmascara to eyelashes, comprising: a twisted wire core holding aplurality of radially extending bristles to form a brush at an end ofthe core, said bristles having a diameter of between about 0.0005 inchto 0.00099 inch and a bristle density of 180−40 bristles per turn.
 11. Abrush for applying mascara to eyelashes, comprising: a twisted wire coreholding a plurality of radially extending bristles to form a brush at anend of the core, said bristles having a diameter of between about 0.001inch to 0.0019 inch and a bristle density of 175−30 bristles per turn.12. A brush for applying mascara to eyelashes, comprising: a twistedwire core holding a plurality of radially extending bristles to form abrush at an end of the core, said bristles having a diameter of betweenabout 0.002 inch to 0.0029 inch and a bristle density of 120−22 bristlesper turn.
 13. A brush for applying mascara to eyelashes, comprising: atwisted wire core holding a plurality of radially extending bristles toform a brush at an end of the core, said bristles having a diameter ofbetween about 0.003 inch to 0.004 inch and a bristle density of 60−18bristles per turn.